HIV-1 (human immunodeficiency virus-1) infection and AIDS (acquired immune deficiency syndrome) remains a major medical problem. According to UNAIDS, at the end of 2014 nearly 37 million people were living with HIV. The number of cases of HIV has risen rapidly. In 2005, approximately 5.0 million new infections were reported, and 3.1 million people died from AIDS. Therefore, novel anti-HIV agents exhibiting distinct resistance patterns, and favorable pharmacokinetic as well as safety profiles are needed to provide more treatment options.
An emerging class of compounds for the treatment of HIV are called HIV maturation inhibitors. Maturation is the last of as many as ten or more steps in HIV replication or the HIV life cycle, in which HIV becomes infectious as a consequence of several HIV protease-mediated cleavage events in the gag protein that ultimately results in release of the capsid (CA) protein. Maturation inhibitors prevent the HIV capsid from properly assembling and maturing, from forming a protective outer coat, or from emerging from human cells. Instead, non-infectious viruses are produced, preventing subsequent cycles of HIV infection.
The HIV maturation triterpenoid compound of Formula 1, below:
has been set forth and described in PCT Patent Application Publication No. WO 2012/106190 A1, published Aug. 9, 2012, and its US equivalents US Patent Application No. US 2013/0035318 A1, published Feb. 7, 2013 and U.S. Pat. No. 8,846,647 B2, issued Sep. 30, 2014, which are incorporated herein by reference. These documents describe and set forth various methods for making the compound of Formula I. This compound is also known by the IUPAC name 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(1,1-dioxidothio morpholino) ethyl)amino)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6, 7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl) benzoic acid.
Although the methods known in the art for producing the compound of Formula I may be useful, new processes are desired that can enhance the efficiency of producing the compound.